How to Add a Data Replication Device Group to a Sun StorageTek Availability Suite Protection Group

Before You Begin

A protection group is the container for the application resource groups, which contain data for services that are protected from disaster. Sun Cluster Geographic Edition software protects the data by replicating it from the primary cluster to the secondary cluster. By adding a Sun Cluster device group to
a protection group, Sun Cluster Geographic Edition software monitors the replication status of all volumes in the device group that belong to a Sun StorageTek Availability Suite volume set. Sun Cluster Geographic Edition software also controls the role and state of the volume set during protection group operations like start, stop, switchover, and takeover.

Before you add a device group to a protection group, ensure that the following conditions are met:

The protection group is defined on the local cluster.

The protection group is offline on the local cluster and the partner cluster, if the partner cluster can be reached.

The device group exists on both the local cluster and the partner cluster.

The Nodelist property of the device group contains the same entries in identical order to the Nodelist property of the protection group.

The Local_logical_host property specifies a valid hostname that can be hosted by the local cluster and that is reserved for this device group.

The Remote_logical_host property specifies a valid hostname that can be hosted by the remote cluster and that has been reserved for this device group.

If the Enable_volume_set property is set to true, then the /var/cluster/geo/avs/avsdg-volset.ini file must exist and contain valid entries on all nodes of both partner clusters. For information about configuring this file,
see Enabling a Sun StorageTek Availability Suite Volume Set.

This command adds a device group to a protection group on the local cluster and propagates the new configuration to the partner cluster if the partner cluster contains a protection group of the same name.

How the Data Replication Subsystem Verifies the Device Group

The device group that Sun StorageTek Availability Suite controls is added to a protection group. The data replication layer verifies that the device group exists and that the value of its Nodelist property contains the same entries in identical order to the Nodelist property
of the protection group.

When the geopg add-device-group command runs, a lightweight resource group for the device group is created and brought online. The lightweight resource group contains the following resources:

A logical hostname resource that is used for data replication, as specified in the Local_logical_host property

An HAStoragePlus resource that controls the collocation of the device group with the lightweight resource group

When you run the geopg add-device-group command, a replication resource of the type GeoCtlAVS is created in the replication resource group of each device group in the protection group and brought online. For information about the format of the replication
resource group, see Sun StorageTek Availability Suite Replication Resource Groups.

The Nodelist property of the lightweight resource group and replication resource group contains the same entries in identical order to the Nodelist property of the protection group.

If a resource or resource group of the same name is already configured on the local cluster, Sun Cluster Geographic Edition verifies the configuration and sets the Configuration to Error if the configuration is not correct.

If the Enable_volume_set property of this device group is set to True, then volume sets that are defined in the /var/cluster/geo/avs/AVS-devicegroup-volset.ini file are enabled. Otherwise, Sun Cluster Geographic Edition software controls and monitors
all volume sets that you enable manually by using the Sun StorageTek Availability Suite commands.

If the geopg add-device-group command is unsuccessful, the configuration of the protection group is not modified.

If the geopg add-device-group command is successful and the Configuration status on the local cluster is set to OK, then the new configuration is propagated to the partner cluster. This propagation causes the whole protection group
configuration to revalidate on the partner cluster. During revalidation, the same entities are created on the partner cluster, including the lightweight resource group and the replication resource group. Volume sets are also enabled on the partner clusters if the /var/cluster/geo/avs/AVS-devicegroup-volset.ini file exists on the partner cluster and contains correctly defined volume sets. If the validation is unsuccessful, then the Configuration status on the partner cluster is set to Error on the partner cluster.

Caution –

Do not use Sun Cluster commands to change, remove, or bring offline these resources or resource groups. Use only Sun Cluster Geographic Edition commands to administer lightweight resource groups, replication resource groups, and resources that are internal entities managed by Sun Cluster Geographic Edition software.
Altering the configuration or state of these entities directly with Sun Cluster commands could result in unrecoverable failure.

If the device group on the partner cluster is validated successfully and the Enable_volume_set property of this device group is set to true, then the volume sets that are defined in the /var/cluster/geo/avs/AVS-devicegroup-volset.ini file
are enabled on the partner cluster. Other volume sets of the device group are disabled.

After the device group has been added to the protection group, you can enable or disable the volume sets of the device group directly by using the Sun StorageTek Availability Suite commands. The /var/cluster/geo/avs/AVS-devicegroup-volset.ini file is used only when the protection group that
contains the device group is successfully validated for the first time.

How to Modify a Sun StorageTek Availability Suite Data Replication Device Group

This command modifies the properties of a device group in a protection group on the local cluster. Then the command propagates the new configuration to the partner cluster if the partner cluster contains a protection group of the same name.

Specifies the name of the protection group that will contain the new data replication device group.

How to Delete a Data Replication Device Group From a Sun StorageTek Availability Suite Protection Group

Before You Begin

You might need to delete a data replication device group from a protection group if you added a data replication device group to a protection group. Normally, after an application is configured to write to a set of disks, you would not change the disks.

Before you remove a data replication device group, ensure that the following conditions are met:

The protection group is defined on the local cluster.

The protection group is offline on the local cluster and the partner cluster, if the partner cluster can be reached.

This command removes a device group from a protection group on the local cluster. Then the command propagates the new configuration to the partner cluster if the partner cluster contains a protection group of the same name.

This command
removes the device group from the protection group. This command also disables all volume sets associated with the device group and deletes the lightweight resource group and replication resource group for this device group.

# geopg remove-device-group AVSdevicegroupnameprotectiongroupname

AVSdevicegroupname

Specifies the name of the data replication device group

protectiongroupname

Specifies the name of the protection group

Example 2–10 Deleting a Replication Device Group From a Sun StorageTek Availability Suite Protection Group

This example deletes a data replication device group from a Sun StorageTek Availability Suite protection group.